Documentation/git-for-each-ref: clarify peeling of tags for --format

[thirdparty/git.git] / Documentation / git-for-each-ref.txt

git-for-each-ref(1)
===================

NAME
----
git-for-each-ref - Output information on each ref

SYNOPSIS
--------
[verse]
'git for-each-ref' [--count=<count>] [--shell|--perl|--python|--tcl]
		   [(--sort=<key>)...] [--format=<format>] [<pattern>...]
		   [--points-at <object>] [(--merged | --no-merged) [<object>]]
		   [--contains [<object>]] [--no-contains [<object>]]

DESCRIPTION
-----------

Iterate over all refs that match `<pattern>` and show them
according to the given `<format>`, after sorting them according
to the given set of `<key>`.  If `<count>` is given, stop after
showing that many refs.  The interpolated values in `<format>`
can optionally be quoted as string literals in the specified
host language allowing their direct evaluation in that language.

OPTIONS
-------
<count>::
	By default the command shows all refs that match
	`<pattern>`.  This option makes it stop after showing
	that many refs.

<key>::
	A field name to sort on.  Prefix `-` to sort in
	descending order of the value.  When unspecified,
	`refname` is used.  You may use the --sort=<key> option
	multiple times, in which case the last key becomes the primary
	key.

<format>::
	A string that interpolates `%(fieldname)` from a ref being shown
	and the object it points at.  If `fieldname`
	is prefixed with an asterisk (`*`) and the ref points
	at a tag object, use the value for the field in the object
	which the tag object refers to (instead of the field in the tag object).
	When unspecified, `<format>` defaults to
	`%(objectname) SPC %(objecttype) TAB %(refname)`.
	It also interpolates `%%` to `%`, and `%xx` where `xx`
	are hex digits interpolates to character with hex code
	`xx`; for example `%00` interpolates to `\0` (NUL),
	`%09` to `\t` (TAB) and `%0a` to `\n` (LF).

<pattern>...::
	If one or more patterns are given, only refs are shown that
	match against at least one pattern, either using fnmatch(3) or
	literally, in the latter case matching completely or from the
	beginning up to a slash.

--shell::
--perl::
--python::
--tcl::
	If given, strings that substitute `%(fieldname)`
	placeholders are quoted as string literals suitable for
	the specified host language.  This is meant to produce
	a scriptlet that can directly be `eval`ed.

--points-at <object>::
	Only list refs which points at the given object.

--merged [<object>]::
	Only list refs whose tips are reachable from the
	specified commit (HEAD if not specified),
	incompatible with `--no-merged`.

--no-merged [<object>]::
	Only list refs whose tips are not reachable from the
	specified commit (HEAD if not specified),
	incompatible with `--merged`.

--contains [<object>]::
	Only list refs which contain the specified commit (HEAD if not
	specified).

--no-contains [<object>]::
	Only list refs which don't contain the specified commit (HEAD
	if not specified).

--ignore-case::
	Sorting and filtering refs are case insensitive.

FIELD NAMES
-----------

Various values from structured fields in referenced objects can
be used to interpolate into the resulting output, or as sort
keys.

For all objects, the following names can be used:

refname::
	The name of the ref (the part after $GIT_DIR/).
	For a non-ambiguous short name of the ref append `:short`.
	The option core.warnAmbiguousRefs is used to select the strict
	abbreviation mode. If `lstrip=<N>` (`rstrip=<N>`) is appended, strips `<N>`
	slash-separated path components from the front (back) of the refname
	(e.g. `%(refname:lstrip=2)` turns `refs/tags/foo` into `foo` and
	`%(refname:rstrip=2)` turns `refs/tags/foo` into `refs`).
	If `<N>` is a negative number, strip as many path components as
	necessary from the specified end to leave `-<N>` path components
	(e.g. `%(refname:lstrip=-2)` turns
	`refs/tags/foo` into `tags/foo` and `%(refname:rstrip=-1)`
	turns `refs/tags/foo` into `refs`). When the ref does not have
	enough components, the result becomes an empty string if
	stripping with positive <N>, or it becomes the full refname if
	stripping with negative <N>.  Neither is an error.
+
`strip` can be used as a synomym to `lstrip`.

objecttype::
	The type of the object (`blob`, `tree`, `commit`, `tag`).

objectsize::
	The size of the object (the same as 'git cat-file -s' reports).

objectname::
	The object name (aka SHA-1).
	For a non-ambiguous abbreviation of the object name append `:short`.
	For an abbreviation of the object name with desired length append
	`:short=<length>`, where the minimum length is MINIMUM_ABBREV. The
	length may be exceeded to ensure unique object names.

upstream::
	The name of a local ref which can be considered ``upstream''
	from the displayed ref. Respects `:short`, `:lstrip` and
	`:rstrip` in the same way as `refname` above.  Additionally
	respects `:track` to show "[ahead N, behind M]" and
	`:trackshort` to show the terse version: ">" (ahead), "<"
	(behind), "<>" (ahead and behind), or "=" (in sync). `:track`
	also prints "[gone]" whenever unknown upstream ref is
	encountered. Append `:track,nobracket` to show tracking
	information without brackets (i.e "ahead N, behind M").  Has
	no effect if the ref does not have tracking information
	associated with it.  All the options apart from `nobracket`
	are mutually exclusive, but if used together the last option
	is selected.

push::
	The name of a local ref which represents the `@{push}`
	location for the displayed ref. Respects `:short`, `:lstrip`,
	`:rstrip`, `:track`, and `:trackshort` options as `upstream`
	does. Produces an empty string if no `@{push}` ref is
	configured.

HEAD::
	'*' if HEAD matches current ref (the checked out branch), ' '
	otherwise.

color::
	Change output color.  Followed by `:<colorname>`, where names
	are described in `color.branch.*`.

align::
	Left-, middle-, or right-align the content between
	%(align:...) and %(end). The "align:" is followed by
	`width=<width>` and `position=<position>` in any order
	separated by a comma, where the `<position>` is either left,
	right or middle, default being left and `<width>` is the total
	length of the content with alignment. For brevity, the
	"width=" and/or "position=" prefixes may be omitted, and bare
	<width> and <position> used instead.  For instance,
	`%(align:<width>,<position>)`. If the contents length is more
	than the width then no alignment is performed. If used with
	`--quote` everything in between %(align:...) and %(end) is
	quoted, but if nested then only the topmost level performs
	quoting.

if::
	Used as %(if)...%(then)...%(end) or
	%(if)...%(then)...%(else)...%(end).  If there is an atom with
	value or string literal after the %(if) then everything after
	the %(then) is printed, else if the %(else) atom is used, then
	everything after %(else) is printed. We ignore space when
	evaluating the string before %(then), this is useful when we
	use the %(HEAD) atom which prints either "*" or " " and we
	want to apply the 'if' condition only on the 'HEAD' ref.
	Append ":equals=<string>" or ":notequals=<string>" to compare
	the value between the %(if:...) and %(then) atoms with the
	given string.

symref::
	The ref which the given symbolic ref refers to. If not a
	symbolic ref, nothing is printed. Respects the `:short`,
	`:lstrip` and `:rstrip` options in the same way as `refname`
	above.

In addition to the above, for commit and tag objects, the header
field names (`tree`, `parent`, `object`, `type`, and `tag`) can
be used to specify the value in the header field.

For commit and tag objects, the special `creatordate` and `creator`
fields will correspond to the appropriate date or name-email-date tuple
from the `committer` or `tagger` fields depending on the object type.
These are intended for working on a mix of annotated and lightweight tags.

Fields that have name-email-date tuple as its value (`author`,
`committer`, and `tagger`) can be suffixed with `name`, `email`,
and `date` to extract the named component.

The complete message in a commit and tag object is `contents`.
Its first line is `contents:subject`, where subject is the concatenation
of all lines of the commit message up to the first blank line.  The next
line is 'contents:body', where body is all of the lines after the first
blank line.  The optional GPG signature is `contents:signature`.  The
first `N` lines of the message is obtained using `contents:lines=N`.
Additionally, the trailers as interpreted by linkgit:git-interpret-trailers[1]
are obtained as 'contents:trailers'.

For sorting purposes, fields with numeric values sort in numeric order
(`objectsize`, `authordate`, `committerdate`, `creatordate`, `taggerdate`).
All other fields are used to sort in their byte-value order.

There is also an option to sort by versions, this can be done by using
the fieldname `version:refname` or its alias `v:refname`.

In any case, a field name that refers to a field inapplicable to
the object referred by the ref does not cause an error.  It
returns an empty string instead.

As a special case for the date-type fields, you may specify a format for
the date by adding `:` followed by date format name (see the
values the `--date` option to linkgit:git-rev-list[1] takes).

Some atoms like %(align) and %(if) always require a matching %(end).
We call them "opening atoms" and sometimes denote them as %($open).

When a scripting language specific quoting is in effect, everything
between a top-level opening atom and its matching %(end) is evaluated
according to the semantics of the opening atom and only its result
from the top-level is quoted.


EXAMPLES
--------

An example directly producing formatted text.  Show the most recent
3 tagged commits:

------------
#!/bin/sh

git for-each-ref --count=3 --sort='-*authordate' \
--format='From: %(*authorname) %(*authoremail)
Subject: %(*subject)
Date: %(*authordate)
Ref: %(*refname)

%(*body)
' 'refs/tags'
------------


A simple example showing the use of shell eval on the output,
demonstrating the use of --shell.  List the prefixes of all heads:
------------
#!/bin/sh

git for-each-ref --shell --format="ref=%(refname)" refs/heads | \
while read entry
do
	eval "$entry"
	echo `dirname $ref`
done
------------


A bit more elaborate report on tags, demonstrating that the format
may be an entire script:
------------
#!/bin/sh

fmt='
	r=%(refname)
	t=%(*objecttype)
	T=${r#refs/tags/}

	o=%(*objectname)
	n=%(*authorname)
	e=%(*authoremail)
	s=%(*subject)
	d=%(*authordate)
	b=%(*body)

	kind=Tag
	if test "z$t" = z
	then
		# could be a lightweight tag
		t=%(objecttype)
		kind="Lightweight tag"
		o=%(objectname)
		n=%(authorname)
		e=%(authoremail)
		s=%(subject)
		d=%(authordate)
		b=%(body)
	fi
	echo "$kind $T points at a $t object $o"
	if test "z$t" = zcommit
	then
		echo "The commit was authored by $n $e
at $d, and titled

    $s

Its message reads as:
"
		echo "$b" | sed -e "s/^/    /"
		echo
	fi
'

eval=`git for-each-ref --shell --format="$fmt" \
	--sort='*objecttype' \
	--sort=-taggerdate \
	refs/tags`
eval "$eval"
------------


An example to show the usage of %(if)...%(then)...%(else)...%(end).
This prefixes the current branch with a star.

------------
git for-each-ref --format="%(if)%(HEAD)%(then)* %(else)  %(end)%(refname:short)" refs/heads/
------------


An example to show the usage of %(if)...%(then)...%(end).
This prints the authorname, if present.

------------
git for-each-ref --format="%(refname)%(if)%(authorname)%(then) Authored by: %(authorname)%(end)"
------------

SEE ALSO
--------
linkgit:git-show-ref[1]

GIT
---
Part of the linkgit:git[1] suite